Apparatus for the control of fluid-pressure brakes.



I L. V. LEWIS.

APPARATUS FOR THE CONTROL FLUID PRESSURE BRAKES.

APPLICATION may MAY E, m3.

L. V. LEWIS.

APPARATUS FOR THE CONTROL OF FLUID PRESSURE BRAKES.

APPLICATION FILED MAY3.1913- v Patented July 20, 191(1.

4 SHEETSSHEET 2.

L. V. LEWIS.

APPARATUS FOR THE CONTROL OF FLUTD PRESSURE BRAKES.

APPLICATION HLED MAY 8. ma.

1,192,331. Patented July 25, 1916.

v 4 SHEETS-SHEET 3.

L. V. LEWIS.

APPARATUS FOR THE CONTROL OF FLUID PRESSURE BRAKES.

APPLICAHON men MAY 3. 1913.

1,192,331. Patented July 25, 19 16 4 SHEETSSHEET 4.

jknovvn as th.

' STATES PATENT OFFICE.

LLOYD V. LEWIS, 0F K DGEWOOD BOROUGH, PENNSYLVANIA, ASSIGNOR TO'THE UNION SWITCH 82; SIGNAI SCOMBANY, OF SWISSVALE. PENNSYLVANIA. A CORPORATION OF PENNSYLVANIA APPARATUS FOR THE CONTR'QI. OF FLUID-PRESSURE; BRAKES.

Application filed May 8, 1913.

To all whom it may concern Be it known that l, LLOYD V. LEWIS. a citizen of the United States. residing at Edgewood borough. in the. county of Allegheny and State of Pennsylvania. have. invented certain new and useful Improve ments in Apparatus for the Control of Fluiddressure Brakes. of which the following is a specification.

My invention relates to apparatus for the control of fluid pressure brakes for railway vehicles and particularly to apparatus for controlling such brakes automatically, that is. independently of the engineer or driver of the vehicle.

I will describe certain forms of apparatus embodying my invention, and will then point out the novel features. thereof in claims.

In the accompanying drawings, Figure 1 is a view showing one form of apparatus for the control of fluid pressure brakes embodying my invention. Fig. 2 is a view showing in cross-section and on an enlarged scale a brake application valve shown in Fig. 1 and embodying my invention. Fig. 3 is a view showing a modification of a. portion of the brake application valve shown in Fig. 2. Fig. 1+ is a view showing in top plan view a portion of the brake application valve shown in Fig. 2. and Fig. 5 is a similar view showing in bottom plan view a portion of the brake appl' :ation valve shown in Fig. Figs, 6 and 7 are views showing modifications of the apparatus shown in Fig. 1.

' Similar reference characters refer Q0 similar parts in each of the several views.

Referring firs to Fig. l. the reference character l d ignates a reservoir. usually main reservoir. which is upplied with f uid pressure, usually coinprcs sed air. from a Mutable eompre'sor not shown). 3 is a eke pipe t which is connected. by means at a pipe a'valve device 4 known usually as rip-le valve. This triple valve is connect I. by emails of a pipe 36 with an auxiliary reservoir 5. and by means (it a. pipe with a brake cvlinder (3. The pressure in the brake pipe 3 is as usual controlled by an engineers brake valve 2, to v rich the brake pipe 3 is connected by pi w-t 3. 3. and a brake appliea- Specification of Letters Patent.

Patented July 25, 1.916.

Serial No. 766.291.

tion valve 8 hereinafter explained. The engineers brake valve 13 is connected with the reservoir 1 by means of a pipe 37, and also by means of a branch pipe 38 containing a feed valve 7.

The parts of the apparatus which I have thus far mentioned are so well known that causes triple valve 4 to operate to admitfluid-pressure from the auxiliary reservoir 5 to the brake cylinder 6 to produce an application of the brakes.

Referring noW to both Figs. 1 and 2, I will explain the brake application valve 8. This valve device comprises an inclosing casing formed of a body portion 9 provided with two caps 9 and 9, one at each end. These caps are fixed to the body portion, by bolts 10. The section 9 comprises two cylinders 11 and 12. in which are located pistons 15 and 16. respectively. These cylinders are separated by two partitions l3 and 14. which form an intervening chamber i Each partition contains a valve po t 14. one or the other of which ports i by a valve 17 according as the val fixed to a piston 15. The outer earl of rod 15* is sup 'iorted in a bracket 5 liticd in partition 1-4. As here. shown. one face of valve i? is provh &:*l with a gasket 17* v-fhich seats against th .iiu ir rim of valve port 14; tin: valve art 1% 52' is; made of such size that the valve I may enter this port bodily, so that the using of this port is acco'nr plisheil by tlu': peiipiery of the valve 17. The purpose o't this construction is to permil. the valve. 17 to be readily Withdrawn from the valve body. by removing the ca p S1. The piston 15 is biased by a spring 19 to such position that valve 17 seats against the annular rim ll.

The cylinder 12 i rovided near the partition 14 with H. .50 and Lil. which sectional area It pectively. Port 21 is provided with screw threads and as here shown is closed by a pipe plug 21 which may be removed when desired. Port 20 is preferably elongated, as shown in Fig. 4, so that its area is comparatively small and yet so that it is gradually cut oil by the rim 16 when piston 16 moves to the right. Port 21 is preferably rectangular in shape as shown in Fig. 5 so that its area is substantially equal to the area of pipe plug 21. The purpose of these ports will appear hereinafter. The piston 16 has an extended rim 1G which rim, when the piston is in the position shown,does not cover either port 20 or 21, but does cover both ports when the piston moves to the right. \Vhen the piston moves to this latter position the end of the rim 16 seats against a gasket 22 in partition 14, thereby effectively discon' necting chamber 18 from ports 20 and 21 even though valve 17 may not be seated on port 14.

The wall of chamber 18 is provided with a hole 23 which is threaded to receive the threaded end of pipe 3, and the wall of cylinder 11 is also provided with a threaded hole 24 to receive the threaded end of pipe 3". Cap 9 is provided with a threaded hole :28 to receive the threaded end of a pipe 25. and cap 9 is provided with a threaded hole 27 adapted to receive the threaded end of a pipe 26. Pipe 26 leads to the brake cylinder 6, and, therefore, the pressure on the left-hand side of piston 16 is the same as that in the brake cylinder. Pipe 25 leads to a valve de vice 29, which normally closes the end of this pipe, but which valve may at times be opened as hereinafter explained. Pipe 25 is connected with the pipe 38 through the medium of a pipe 30, a cock 30, apipc 32. and an orifice 31 of restricted area. The cock 39 is normally open, hence, the pipe 23 normally contains fluid under the same pressure as that in the brake pipe 3.

The valve device 29 may be of any type which is normally closed and which when opened will remain open until the pressure in pipe 25 has fallen to a' predetermined value, such. for example. as 5 pounds per square inch. This valvc device. as here shown, is similar to the valve device 40 shown and described in my co-pcnding application filed Feb. 13, 101?), Serial No. 748.092. to Which reference may be had for a description of this valve device. Any suitable means may be provided for opening the Villl. device 2!) when it is desired that the brakes should be applied; this means, as well as the specific structure of the valve dc vice 29, form no part of my present invention. As here shown. this means is the same as that shown and described in my co-pending application, Serial No. 748,092. llriefiy described, it comprises an arm 40 mounted on the vehicle and biased by a spring 45 so 40 is raised by a trip 41, the head 43 engages the offset portion of latch 47 and swings this latch late ally on its pivot so that the-latch operates the valve stem 48 to open the valve devic'eQQ.

The operation of'thc valve device 8 and associated apparatus .is as follows: Under normal conditions. that is, when the pressure in pipe 25 is the same as that in brake pipe 3, the fluid pressure on each face of pis ton 15 is the same, hence the spring 19 holds this piston at the extreme left hand position so that-valve port 14 is closed by valve 17.

Valve port 13 is then open. so that pipes 3" and 3 are connected. and the brake pipe I) is. therefore. connected with reservoir 1 through the engineers valve 2. The fluid pressure brakes may then be controlled by the engineer s valve 2 in the usual manner. Yl-Hll valve device 29 is opened, the consequent reduction of pressure in pipe 2:") permits the pressure on the left hand face of piston 1.) to overcome the action of spring 1!) and move this piston to the right. thereby causing valve 17 to open port H and close port 13. The opening of the former port allows lluid fronrchamla-r l to pass into cvlinder 12, and if piston 16 is not at the left hand end of its stroke it is immediately moved there. so that brake pipe 3 is opened to atmosphere through port 20 alone or through both ports 20 and 21. according to whether or not the port 21 is closed by plug :21". The closure of port 13 by valvc lT disconnects pipe 3 from chamber 18. thereby preventing loss of lluid from. the reservoir 1. and also preventing intcrl'crelu-c by the manipulation of the engineer's brake valve 3.

The ross-sectional area of port 20 is such that when port ll is closed by plug 21-", the rate of reduction of pressure in the brake pipe 3 is such as to cause asci-vice" applica tion of the brakes; and the. cross-sectional area of port 21 is such that when this port is open. the rate of reduction of the pressure in brake pipe 3 due to the two ports .20 and 21 is such as to cause an emcrgemgv appliation of the brakes. The purpose of plug 21" is to permit the same valve device 8 to cause an cnu-rgency or a service application of the brakes by merely removing or inserting the plug. 7

, It is well mulcrstood that reduction of the pressure in the brake pipe, 3 below a certain value is a wast: lluid pressure and is undesirable because it results in loss of bra-king power :and loss of time in recharging {the brake pipe to release the brakes. When the pressurein thebruke cylinder 6 begins to ri e; the. piston 16 will r'ncve tothe right itnartiall y closes the exhaust port 3: pg is 20 and "21; this partial closure will 113;, to. retard its further movement The .ec tliction of pressure in the brake pipe 10 3 Will-= lu-be slower. YAs the pressurein the brake cylinder .6 continues. to rise, piston 1(5. Will: he continually -.1"fl0"0(l furtl'ierto the ,7 ight icutting'dcwn the area or theexhaust portfvrn ports, until finally the brake pipe l'b-pressur, .is slightly less than that in the b'rakereyli'nde-r 6, when the piston will .entirely close the exhaust port or ports, and "-':i'urthc Fivu'ste of fluid prevented.

ASthEIGlDbE-fOlB stated, the valve device zofl gmvhen opened, will remain open until -.=th'e ='pressure in pipe 25 hes been reduced below ekpredeterniined value, such, for ex- -a'nnple, its-5 pounds-persquare inch. The of theorifice 31- iss uch' that While cock ''is ep'en, the pressure-in pipe'2'5- will not fall beiew'this predetermined"value; 1 Hence, in o'rderto' release the brak'es tis see My to provide i'neans for reducing the presure in pipe 25 below this predetermined "value.

'I'have here-shown txvu sejara te n'iezins" for eccornplishing this fi1nctidi ,'eitl1er of which may be eu iployed. One o f'thes e means 'is a cock 4;?) by means of whichthe pipe may he opened to atmosphere, thereby i-ificuickly reducing the pressure therein below the predetermined value and so allowingthe valve device 29' to close; if then the cock is egain' closecl, the pressurein pipe'Q-fi will build up and cause'pisten 15 t0 be loag uin moved to the leftby-spring 19, there- ,i.) releasing the brakes. The cock 49 is pref erahly located at a point- "cn the vehicle x-vhi ch can be reached only from the roeclbed, thereby rendering it impossible for a person on, the vehicle to employ this cock tq release the hrikes af-t cr an uutomaticepplication until theirain has been brought to a stop. his obvious. that when valvedevice '29 is closed, the-openin of cock 519 will cause an upplicat inn ofthe brakes. Thectherineans hich I heve here shown for releasing the brakes coihprisesthe cock; This ccclr is preferably located in such p-ositicn that it s, n he easily rciiche iby the driver of the I vehicle when-the driver e'ecupies usual After gin application er" the brakes mse to-zm operation of valve clcv their ing ofvalve device 29,;the normal vpres sure will be maintained-in pipe by;l eakr.

age into this pipe from pipes 3 and? past piston 15, so that after the openingof valve device 2 the same period of t-imezwill elapse before release of the brakes as if this cock were closed at theinor'nent of opening the;

valve devicei29; 1

It sometimes desirable to i'nsurethet a considerable interval 'of time-should elapse between the time that the "cock 39 is closed builds up to such point as toes-use the brakes to release; the reason. fontlu's is' to insure'that the brakes should he-applied foman interval long enough to bring the vehicle'to a standtime intervah i nre ierzibly connect a-reser vcir ivithfpipe 30: Then when-cock 39 is closed flatter a brzike application, a ecu sirlemhle interval of time-will elapse before rthe? pressurein .pipevalue if iolds this interv heiug dete -1 p Y required 'ibr the pressure-iii 'reser\-*o1r-'33=to "reduce th-rcugh the restricted orifice g-lfr'eiu ill fail; beievv' the opened, after which the brakes will be rel'ehsed us hereinhefore explained.

In some braking systems, a vieryhigh' pressure, for eiainple, 110 pounds per square inch, is'emplcyed inthe breke pipeQvvhil'e a comparatively lovv. pressure, for exzimple, 45

, pounds persquare inch, is used in theloco motive brake cylinders," \Vith this valve cl brake pipe pressure, Jthepissiir' in the brake cylinders of the rest-of thetrnin equalizes with the brake pipe pressure ati bout 78 pounds per square inch for service z pplicatiou. Hence, in order to preventfu'rther l ss of fluid .When the brake pipe pressure falls to 78p0undsfit is necessarvto make 45 p unds' on the left side offpiston balance '78 pounds on the right; this may be accomplished by making the piston differential irr fcriu, as shown -1I1 F g.3, in which the area of the left handfaceof piston 16 greuerthan the ureiofitheright hand it) prope ly prcportioning the areas oi the two piston faces, any desired brake "ripe prcssu e may be balanced by any brake inder pressurejhence :l service applicaor auv desired valu'einay be obtained, frmn u verv light to a. full service applicatti s Hie form of application shown in Fi i. a modification 0? that shown in Fig. l.

in dig. 6, fluid pressure is supplied to pipe 89 and the time that the pressure in pipe 25,;

25 trompipe 3" by means of an orifice 51 in piston l the-connection between pipe-25 and feed pipe 38 being omitted.

, The operation of the apparatus shown in Fig. 6 is as follows: 'When valve device 29 is opened. the consequent reduction of pressure in pipe 225 permits the pressure on the left-hand face of piston to move this piston to the right. thereby opening port 14 and causing a brake application as before. Valve device 29 is held in the open position by. lluid supplied from pipe.3-" through orifice 51 and pipe .25, and piston 15 is therefor held'in the right hand position. The release of the brakes may be accomplished by the driver of the vehicle in the following manner. The driver first moves valve 2 to the emergency position. thereby opening pipe 3" to atmosphere. The source of supply of lluid for pipe being thus cut oil,

the pressure in this pipe. soon falls to the point at which valve device 29 closes: then the pressure of the fluid on'the two sides of piston 15 becomes equalized at a low valuc,'

but the piston does not return to the left because of the brake pipe pressure. acting on the left hand fare of valve 17. The driver then returns valve 2 to the running position thereby permitting thepressure in pipe 3 to build up. and thereby gradually lmildiug up the pressure in pipe 25. The pressures on both sides of valve 15, and on both sides of valve 17 then being equalized. the spring 19 becomes ell'ective. to move piston 15 to the left thereby permitting release of the brakes.

in the modificationpf my invention shown in Fig. 7. the piston 16 instead of being controlled by the pressure in brake cylinder (3, is'controlled by the pressure in two reservoirs 53 and 53". the. latter of which is connected with the let t hand end of cylinder 8 by a pipe 5 The pressures in reservoirs 53" and 53 are controlled-by a slide valve 58, which is operated by a piston-5G movable in a cylinder (30. The left hand end of eylinder 60 is connected with the brake pipe 3 by a pipe 55 and pipe 3".

The. operation of the apparatus shown in Fig. 7 is as follows: \Vhen valve device 29 is closed and valvc 2 is the running position. piston 56 and slide valve 58 occupy the position shown in the drawing. so that reservoir 53 is open to atmosphere through port 59 and reservoir 53 is in communication with brake pipe 3 through a bypass 57 and pipe 55. The pressures on each side of piston 56 a re, then the same. Hence, the prossmc in reservoir 53 is the same as that in brake pipe 3; this pressure I will assume to be 70 pounds per square inch. When valve device 29 is opened. the consequcnt reduct1on of pressure in pipe 525 permits piston 15 to be moved to the right thereby opening brake pipe 3 to atmosphere through port 20 or through ports .50 and .21. The consequent,

reduction in the brake pipe 3 causes triple valve 4 to cause application of the brakes, and also causes reduction of pressure in cylinder 60 so that the pressure on the righthand face of piston 56 exceeds that on the left-hand-faec, and this piston is-then moved to the left, thereby disconnecting reservoir 53 from atmosphere and connecting it with reservoir 53. Fluid then flows from reservoir 53' to reservoir 53", until the pressures in these two reservoirs are equal. As the n-essurc on the right hand face of piston 56 is reduced by the flow of fluid from reservoir 53 into reservoir 53". the pressure on theleft 'hand face of this piston is also reduced by the outflow of fluid from the brake pi 3,- consequently piston 56 remains in its 1e t-hand position. The relative sizes of these reservoirs may be such that this equalization occurs at any desired pressure. When the pressure in reservoir 53"begins to rise. it causes piston 16 to move tothe right,

partially closing port 20 or ports 20 and 21,

and this partial closure retards further movement of the piston 16 because it causes increase of pressure in cylinder 12; the, reduction of pressure in brake pipe 3 tlie n takes place more slowly. As the pressure in reservoir 53" continues to rise. piston lGjiSi initial value, and this building up causes piston 56 to move back to its initial position, thereby again connecting reservoir 53 with atmosphere. The pressure in reservoir 53"- then builds up to its initial value, and the parts of the apparatus are again in their initial positions and conditions.

Although I have herein shown and described only certain forms and arrangements of apparatus embodying my invention, it is understood tlHltViHiOllS changes and modifications maybe made therein within the scope of the appended claims without departing from the spirit and scope of my 1nvention.

Having thus described my lnventlon, what I claim is: w I

1. In fluid pressure braking apparatus for ra'ilway vehicles, a brake. pipe and a brake cylinder, means for permitting reduction of the. pressure in the brake pipe for causing the admission of fluid pressure to the brake cylinder. and means controlled by the relation between brake pipe pressure and the pressure in the brake cylinder for lim iting the reduction of pressure in the brake pipe.

2. In fluid pressure braking apparatus for railway vehicles, a, brake pipe and a brake cylinder, a valve cylinder, an. exhaustport therein, a piston movable in the valve cylinder and adapted to cover or uncover the port, means for exposing one side of said piston to brake pipe pressure to tend to move the piston to uncover the port, and means for exposing the other side of the piston to the pressure in the brake cylinder.

5%, In fluid pressure braking apparatus for railway vehicles, a brake pipe and a brake cylinder, a valve device comprising a valve cylinder, a port in the latter cylinder, a piston adapted to move in the latter cylinder and to uncover or cover the port,n1eans for connecting the brake pipe with such end of the valve cylinder that the pressure in said pipe tends to move the piston to uncover the port so that the brake pipe pressure is reduced through said port, and means for connecting the brake cylinder with the valve cylinder on the other side of the piston so that when the brake cylinder pressure reaches a predetermined value the piston is moved to close the port thereby stopping the reduction of pressure in the brake pipe.

4. In fluid pressure braking apparatus for railway vehicles, a brake pipe and a brake cylinder, a valve cylinder and a piston movable therein, an exhaust port controlled by the piston for permitting reduction of pressure in the brake pipe, means for at times exposing such face of said piston to brake pipe pressure as to move the piston to open the said port, and means forexposing the other face of the piston to the pressure in the brake cylinder.

5. In fluid pressure braking apparatus for railway vehicles, a brake pipe and a brake cylinder, a valve cylinder and a piston movable therein the two sides of said piston being of ditlercnt areas. a port controlled by said piston for permitting reduction of pressure in the brake pipe, means for sult-jecting such face of said piston to brake pipe pres-- sure as to move the piston to open the port,

and means for subjecting the other face of the piston to the pressure in the brake cylinder.

6. Fluid pressure braking apparatus for Vehicles, comprising a pipe normally supplied with fluid pressure, means controlled by a reduction of pressure in said pipe for causing an application of the brakes, a" valve device for opening," said pipe, said valve dei e when opened being held open by the .d pressure in the pipe until the fluid pres ire in the pipe is reduced to a predetermined value, a reservoir connected with said pipe through a restricted orifice, a source of as fluid pressure, and means for connecting said source with and disconnecting it from the reservoir.

7. Fluid pressure braking apparatus for vehicles, comprising a pipe normally suplied with fluid pressure, means controlled by a reduction of pressure in said pipe for causing an application of the brakes, a valve device for opening said 'pipe, said valve device when opened being held open by the fiuid pressure in the pipe until the fluid pressure in the pipe is vreduced to a predetermined value, a source of fluid pressure, means for connecting said source with and disconnecting it from the said pipe, and an orifice of restricted area interposed between the source and the pipe.

8. Fluid pressure braking apparatus for vehicles. comprising a pipe normally snpplied with fluid pressure, a brake application valve responsive to a reduction of pressure in said pipe to cause a brake application, a valve device for opening said pipe which valve device when opened is held open by the fluid pressure in the pipe until the fluid pressure in the pipe is reduced to a predetermined value, means for opening said valve device, a reservoir connected with the pipe through a restricted orifice, a source of fluid pressure/and a cock for connecting said source with and disconnecting it from the reservoir.

9. In fluid pressure braking apparatus for railway vehicles, a brake pipe, means for permitting reduction of the pressure in the brake pipe, a reservoir, means controlled by reduction of pressure in the brake pipe for increasing the pressure in said. reservoir, and means controlled by the relation between the brake pipe pressure and the pressure in said reservoir for limiting the reduction of pressure in the brake 10. In fluid pressure braking apparatus for railways, a brake pipe, means for re during the pressure in the brake pipe, two reservoirs. means controlled by pressure in the brake pipe for connecting one of said reservoirs with the brake pipe and the other with atmosphere, said last-mentioned means being responsive to reduction of pressure in the brake pipe to disconnect the first reservoir from the brake pipe and the second from atmosphere and to. connect the two reservoirs together, and means controlled by the relation between the brake pipe pressure and the pressure in the second reservoir for limiting the reduction of pressure in the brake pipe.

11. In fluid pressure braking apparatus for railways, a brake pipe, means for reducing the pressure in the brake pipe, two reservoirs, a valve device adapted when in one "position to connect one reservoir with the brake pipe and the other with atmosphere, and when in another position to disconnect the first reservoir from the brake pipe and the second from atmosphere and connect the two reservoirs together;- a cylinder connected withthe brake plpe, a piston in the cylinder and operatively connected with the said valve device, said piston when subjected to the normal brake pipe pressure being held in such position that the valve device occupies its first-mentioned position, and said piston being responsive to reduction of pres-,

sure to move to such position that the valve device occupies the second-mentioned position, and means controlled by the relation between the brake pipe pressure and the pressure in the second reservoir for limiting the reduction of pressure in the brake pipe.

12. Fluid pressure braking apparatus for controlled by reduction of pressure in the brake pipe for increasing the pressure in said reservoir.

13. Fluid pressure braking apparatus for railway vehicles, comprising a brake pipe,a valve cylinder and a piston movable therein, an exhaust port controlled by the piston for permitting reduction of pressure in the brake pipe, meanfii for at times exposing one faceof said piston to brake pipe pressure to move the piston to such position that it opens said port, a reservoir to the pressure in which the other side of said piston is exposed, and means controlled by reduction of pressure in the brake pipe for raising the pressure in said reservoir whereby the said piston is moved to such position that it covers the port.

In testimony whereof I aflix my signature in presence of two witnesses.

LLOYD V. LEWIS.

Witnesses:

BERTIIA R. CUNNINGHAM, A. HERMAN WVEGNER. 

